Circuit breaker



Oct. 11, 1938. J. G. JACKSON CIRCUIT BREAKER Filed Aug. 15. 1935 5 Sheets-Sheet 1 J INVENTOR.

J'olz2z 67 J'ac/Psozz BY'% I Oct. 11, 1938. J. G. JACKSON 2,132,625

CIRCUIT BREAKER Filed Aug. 15, 1935 3 Sheets-Sheet 2 A TTORNY.

Oct. 11, 1938. J. G. JACKSON 2,132,625

0 IRCUIT BREAKER A TTORNEY.

Patented Oct. 11, 1938 UNITED STATES PATENT OFFICE Square D Company, tion of Michigan Detroit, Mich., a corpora- Application August 15, 1935, Serial No. 36,247 Ciaims. (c1. zoo-116) 'Ihis invention relates 'to automatic electric circuit breakers and has for its object the provision of an improved multicircuit circuit breaker.

Another object of this invention is to provide an economicai automatic electric circuit breaker having a minimum of parts.

Another object of this invention is to provide a multi-circuit circuit breaker utilizing a common contact and a plura1ity of individual contacts for the individual circuits.

Another object of this invention is to provide a multi-circuit circuit breaker with a plurality of individual mechanisms, certain of whose contacts are at least electricaily common.

Another object of this invention is to provide a multi-circuit"circuit breaker with a main and a plurality oi brancb circuit breaker mechanisms. the load contact of the main and the line contacts 01 the branch circuits being common.

Another object of this invention is to provide an improved enclosure mounting for an electric circuit breaker.

Another obJect of the invention is the provision et a circuit breaker assemblage within a unitary sealable enclosure having. electricaily connected stationary contact surfaces with individual movable contacts cooperatins therewith and with individual automaticaily and manualiy operable circuit breaker mechanisms for actuating the movable contacts.

Another obJect of the invention is the provision of an improved form of multi-circuit circuit breaker or circuit breaker assemblage pro- 0 viding certain electricaily common parts and having structural mounting details characterized by the compactness and simplicity of the parts resulting in economy of manufacture without sacrificing the performance characteristics of the device.

Another object of the invention is an electric circuit breaker assemblage characterized by centrally disposed, electricaily connected, contact surfaces with automaticaily and manually operable circuit breaker mechansms at opposite sides of the contact surfaces and including movable contacts cooperating with the contact surfaces, the parts being mounted within an enclosure having electricai insulating and arc confining elements and common arc gas venting portions.

Anothr object of the invention lies in the provision of simplified and economicai means for forming an enclosure for a circuit breaker assemblage so as to substantiaiiy prevent access A art from the following specification and appendof the circuit wires.

to the interior of the enclosure and to provide arc isolating and venting portions.

Other objects and features of this invention Wi11 be readily apparent to those skilled in the ed drawings illustrating certain preferred em 5 bodiments of the invention in which:

Figure 1 is a front elevationai view of the breaker according to the present invention with parts of the cover broken away to show the 1 breaker interior.

Figure 2 is a vertical sectional view taken on the line IIII of Figure 1.

Figure 3 is a vertical sectiona] view of a single breaker mechanism showing the operating parts u in over-load tripped position.

Figure 4 is a vertical sectiona] view of the single breaker mechanism showing the parts in reset position before the contacts are ciosed.

Figure 5 is a horizontal sectionai view on line VV of Figure 1.

Figure 6 is a fragmentary sectionai view similar to Figure 5 showing a slightly modifled construction.

Figure 7 is a detailed view of a magnetic arc suppressor plate.

The circuit breaker according to the present invention comprises an outside enclosing box l having a cover 2 hingediy mounted thereon. Within this box is disposed a sealable multi- 30 circuit circuit breaker comprised of an insulating base 3 and a metal cover 4. The cover 4 is adapted to be sealabiy attached to the base 3 by means of rivets 5. The cover 4 extends across the width of the box and to one side there is riveted or otherwise attached a hinge 6 which is bolted to the side walls of the box as at 1. The opposite side of the metal cover 4 15 provided with a fiange 8 carrying a boit 9 adapted to be received within a slot l I in, the box wall to secure the cover 4 and breaker mechanisms within the box I. The cover 4 is provided with a plurality of openings through which extend the push button handles l2 for operatiug the breaker mechanisms. The box cover 2 il; provide.d with a generaily centra] opening which ciosely receives a slightly raised portion 13 in the cover 4 so that the operating push button handles l2 extend to the box exterior. The hinged mounting of the metal cover 4 permits the circuit breaker to be swung to the exterior of the box to facilitate pulling in and connecting To then secure the circuit breaker within the box interior it is swung back to its interior position with the boit 9 redeived within the slot Il whereupon tightening of the boit 9 will secure the circuit breaker in j position.

The individual circuit breaker mechanisms comprise a movable contact bar la carrying a contact tip l5 adapted to engage with a common stationary contact l6 which is rigidly secured to the base by means of a boit Il. The free end of the contact bar Id is normally latched in the position shown at the bottom of Figure 2 by the bimetallic current responsive member l8. The bimetallic strip [8 is rigidly welded or other- Wise secured to an arm l9 centrally punched or otherwise spaced from themain part of a con nector 2! which is rigidiy secured to the base by means of rivet 22. The side arms thus formed at the end of the connector 2! are bent over as at 23 and within the space formed between the connecter 21, the bent-over portions 23 and the arm l9 is disposed a block 24 through which is threaded astud 25 bearing against the free end of arm l9 and thus serving as an adjusting or calibrating means for the bimetaliic strip. Within the rivet 22 is threaded a stud 26 forming the terminal for the breaker. A flexible lead 21 corinects the free end of bimetallic strip l8 with the contact bar l l adjacent to a pivot point thereof to be hereinafter described. The portion of the bar 3 between the lead 21 and the bimetal l3 is provided with holes or otherwiseto provide a high contact pressure without unduiy increasing the pressure between the bar and the bimetallic latching member.

For operating the contact bar M there is provided a generally U-shaped member 29 having legs of difierent lengths. The longer leg of the inember 29 is provided with a slot 3! in which the contact bar is disposed. The upper portion of the bar within this slot is provided with a notch 32 engaging the end of the slot and serving to restrain the bar from longitudinal movement as well as to provide a pivot point for movement of the bar to automatically trip and reset positiens.- .The short; leg of the Uhaped member is also slotted to receive the contact bar in overload;;position as more particularly shown in Figure-f3- the bar l41 and with suitable projections for holding and guiding the member 29 in its re 'ci'procal movement.

In front of the operating member 29 is provided an L-shaped push button handle I2 having its leg extending through the cover A. The base of the handle. [2 is provided Withfa groove 34 .mouiited over a projection 35 on the closed end of the member 29. A small compression spring 36 is disposed within the handle base and bears against the under side of cover 4 in position to normally maintain the upper side of the base a definite distance fromth cover. The ends of the base of the L are provided with smooth curves to facilitate rotation of the push button handle about an axis at right angles and the adjacent curved portion of the L-shaped handle are of a size to fit snugly within the opening in the cover 4. The remaining portion of the base as at 31 is enlarged and in the rotated position of the handle forms fianges bearing against the edges of the opening. A colored ring 38 may be placed on the outwardly projecting leg of the handle for. a purpose to be hereinafter described. V

The operation of this single 'circuit breaker mechanism will now be described in detail.

The mechanism shown at the bottom of Figure 2 is in the normal closed operating position.

In the circuit breaker at the top of Figure 2 the handle l2 has been rotated degrees so that the end of the,base of the handle now bears upon the closed end of the member 29 with the enlarged portion 31 forced against the under side of cover S by spring28. This in efiect forms a simple toggle and the parts are maintained in this position. As the lengthzof the base of the handle from enlargement of portion to the end is greater than the distance between member 29 and cover 4 in the normal operating position, the member 29 has been moved toward the base moving the-contact bar [4 by engagement of the end of slot 3l with notch 32 in the bar.

In this movement the bar pivotsaboutits engagement with the bimetallicmember 18 and assumes the position shown in, the upper circuit b,reaker in Figure2 which is the manual ofi position. In again closing' the circuit through the breaker it is only necessary to fiip the handle back 909 to the position shown in the lower circuit breaker in Figure 2 whereupon the contact bar Hi is moved upwardly to the position therein shown. under action.0f the compression spring 28. 'When an over-load .is passed through the circuitbreaker it -becomes heated and is deflectedawayirom the contact bar M thusreleasing the. end thereof and permitting this end to move away fromathemain body of the base 3. This movement of thecontact bar I 4 is caused by the compressionspring28-and the bar M movesaboutthe engagement ofthe notch 32 with the top of the slot 3l intothe position shown in Figure 3. The'upward'mo- -ment of the contact bar is restrained only :by

its engagement with member 29 WhiCh .presses against the base 'of -thepush buttonhandle [2; As the spring 36 is relatively Weak as compared with the spring 28, the base of the handle' Will be moved against the under side of the cover 4 and the pver-load tripped condition of the breaker will be indicated by the extendedpmsition of the arm ofthe handle which brings the colored ring 38 into View above the cover. To reset the breaker mechanismit is necessary only to press inwardiy upon the'push button handle [2. In the extreme inward movement of the handle, the parts assume the reset rosition shown in Figure 4 with theend cf the"contact bar again in a position to have its upward movement restrained by' thebimetallic member I8 and with the contact tip'separated frointhe stationary contact; 16. -W hen the handl is i- By this, method of resetting it is obviouslyini possible to prevent"the automatic tripping of the breaker by holding the operting handle as the contacts are not engaged to close the circuit until the operating handle m0ves'tb its normal operating position. If the push button handle is pushed inwardiy and held there the contacts simpiy remain separated as shown in Figure 4. If the operating handie should be held in its nonindicating position as shown in the lower portion of Figure 2 the contacts will separate to the same extent although the now free end of the contact bar will not move to its full upward position until the handie is released. However, the contact carrying end of the bar will stiil move against the main body of the base and separate the contacts.

The connection of the flexible lead 21 to an intermediate point on the bar [4 serves two functions as it not only lessens the movement of the lead, but aiso by by-passing a length of the bar places its resistance in the circuit through the latching engagement. This resistance may be increased in any desired manner, one simple means being, as shown, the reduction in the cross section of the bar between its latching end and the point of connection of the flexible lead.

Guides or stops H! and 20 are provided at the ends of the bar l 4. These limit and guide the longitudinal movement of the bar. The limiting stop ID also provides a positive pivot point for the bar in its movement to reset position. The stop 20 also prevents the bar moving with the bimetal where there is play at the notch 32.

In the multi-circuit circuit breaker according to the present invention, a plurality of circuit breaker mechanisms are mounted upon base 3. In the specific example herein disciosed the base is provided with a generally central dividing wall 39 which divides the mechanism into two duplicate and electrically separate parts each of which may be regarded as a multicircuit circuit breaker. In the specific example herein shown and described four individual circuit breaker mechanisms are provided. The

stationary contacts are here in the form of a single large stationar contact l6 with which the four movable contacts l5 cooperate. It is, of course, within the spirit of the present invention that in a muiti-circult circuit breaker a plurality of contacts electrically joined together could be used. However, it is preferred to use contacts having a common mechanical mounting and for this purpose the single contact plate shown as at i6 in the drawings is preferred. This latter construction not only results in a considerable saving of parts and mountingeconomies but also due to its large mass considerably limits the heating due to any one contact as the heat generated will be distributed throughout the large mass of the contact and will have a greater surface from which to be dissipated.

Describing now the multi-circuit circuit breaker shown at one side of the dividing wall 39, there is provided a central wall -4l having a cutout portion 42 in which is maintained the contact l6. The boit l1 projects upwardiy through the central portion of the wall 4! and rigidly secures the contact to the base. The

opening through which the boit I1 projects may then be waxed to provide insulation. Between the contact l6 and the supporting portion of the wall 4! is disposed an insulating strip 43 having cutout portions through which the movable contacts project to engage the contact l6. The insulating strip 43 projects beyond the contact l6 on b0th sides of the wall 4! to the member 29 and in combination with the walls of the base forms an arc chamber. This arrangement permits the discharge of gas from the rupdouble H shape shown in Figure 7.

turing of a single breaker into the space occupled by the multiple group of breakers thus rendering less necessary any important discharge vent to the outer air. 'Ihe central wall 4! may be integral with certain ofthe walls 33 and in this construction the walls 33 may be considered to form projections upon the side walls of the base and the wall 4| rather than as unitary walls slotted to receive the member l4. The ends of the breaker are provided with fibre shields 45 extending between the base 3 and the cover 4 and sealable therewith by rivet 5.

In the multi-circuit circuit breaker as hereinbefore described, it is provided that one breaker mechanism may be a main breaker and feed' from the line to the stationary contact 16. The three other circuit breaker mechanisms of each breaker will then constitute branch circuit breakers leading from the contact [6 to the individual branch circuits. The contact l6 here forms the load side of the main breaker and the line side of the branch breakers. The circuit breaker is sealable and it is impossible to place a short directly on the load side of the main breaker or the line side of the branch breakers but any short must occur on the load side of the branch breakers and there will always be two circuit breaker mechanisms in series with any short which may occur. This is a desirable safaty factor and it is in conformance with many safety requirements Which require main as well as branch circuitprotection.

A slightly modifiedform of construction is shown in Figure 6 wherein a connector 46 extends through the side wall of the breaker and is rigidly secured to the contact le by boit I1. This connector 46 may serve as a tap on the load side of the main breaker if the feeding is as heretofore described. However, it may 50metimes be desired to omit what has been termed the main breaker and feed'directly through the four individual breakers to the branch circuits. The connector 46 wouid then serve as the incoming'main connected directly to the contact I6 and the branch circuit breakers would then lead directly from the main to the branch circuits. In the case where the connector 46 is 9. tan .2 saiety factor is lost as it is now possible to place a short on the load side of the main breaker where only one circuit breaker mechanism will be in series with the short, also where the connector 46 is used as a line lead-in the safety 01 the main breaker is lost.

Also'shown in Figure 6 is a magnetic plate 41 placed beneath the contact I6. While thls plate may be of unitary construction it is pre1erred to form it as here shown of a plurality of thin laminated magnetic sheets, having no insulation other than incidente] air space and incidental surface oxide. As here shown the fibre plate 43 insulates the magnetic plate 41 from the contact [6. In some instances .it might be desirable to mount the p ate 41 directly against the contact I6 in which case the fibre sheet will be omitted. The plate 41 is out out to provide passage for the movable contacts and takes the Further arc suppressing means are embodied by the insulating plates 48 disposed closely adjacent to the path of movement of the movable contacts and on either side thereof. These insulating plates serve to confine and cool the arc drawn between the separated contacts. While the circuit breaker shown in Figure 6 embodies both the magnetic and parallel plate arc suppressing means it is readily understood that either or both of them may be omitted from the circuit breaker assembly.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims:

What is claimed is:

1. In a unitary, automatic multi-circuit circuit breaker, a base, a plurality of individual automatically and manually operable electric circuit breaker mechanisms supported by said base, means cooperating with said base to form an enclosure for said mechanisms sealed from outside access, said mechanisms having e1ectrically common parts at the same electrical potential and connected to feed from said common parts through the individual mechanisms to individual branch circuits.

2. In a unitary, automatic multi-circuit circuit breaker, a base, a plurality of individual automatically and manuaily operabie electric circuit breaker mechanisms supported by said base, means cooperating With said base to form an enclosure sealed from outside access, said mechanisms having electrically common parts within the enclosure at the same electrical potential, terminals at the exterior of the enclosure, said mechanisms being connected between said e1ectrically common parts and said exterior terminals t individually feed thereto.

3. In a unitary automatic multi-circuit circuit breaker, a base, a plurality of individual circuit breaker mechanisms supported by said base, individual movable contacts actuated by said mechanisms, the cooperating contacts being at least electrically common and supported within the circuit breaker enclosure.

4. In a unitary automatic multi-circuit circuit breaker, a base, a plurality of individual circuit breaker mechanisms supported by said base, individual movable contacts actuated by said mechanisms and a common stationary contact supporting a plurality of contact surfaces in position to be engaged by said movable contacts.

5. In a unitary automatic multi-circuit circuit breaker, a base, a plurality of iridividual circuit breaker mechanisms supported by said base within a sealable enclosure, .individual movable contacts actuated by said mechanisms, at least some of said contacts being load contacts for their corresponding breaker mechanisms, and cooperating, stationary line contacts for at least said corresponding breaker mechanisms which are at least electrically common and supported within the sealable enclosure.

6. In an automatic multi-circuit circuit breakel, a base, a main circuit breaker mechanism supported by said base, a plurality of branch circuit breaker mechanisms supported by said base, each of said mechanisms including cooperating contacts automaticaily ,separable in response to a current overload, the load contact of the main breaker and the line contacts of the branch breakers being at least electrically common and sealable within the circuit breaker interior.

7. In an automatic multi-circuit circuit breaker, 2, base, a main circuit breaker mechanism supported by said base, a plurality cf branch cirable within the circuit breaker interior and con stituting the load contact 01 the mainbreaker andthe line contacts of the branch breakers.

8. In an automatic multi-circuit circuit breaker, a base, a main circuit breaker mechanism,

supported by said base, a plurality of branch circuit breaker mechanisms supported by said base, each of said mechanisms including a contact automatically movable in response to a current overioad, a common stationary contact within the circuit breaker interior and constituting the load contact 01 the main breaker and the line contacts of the branch breakers and a connector secured to said stationary contact and extending to the exterior of the breaker.

9. In a unitary automatic 1nulti-circuit circuit breaker, an enclosure sealed from outside access, a plurality of movable contacts in said enclosure, separate operating means for said movable contacts including manually operablehandles projecting irom said enclosure and current responsive elements for automatically releasing said movable contacts on overload, and atleast elec= trically common stationary contacts within said enclosure in position to be engaged by said movable contacts.

' 10. In a unitary automaticmuiti-circuit circuit breaker, an enclosure, a plurality of movable con= tacts in said enclosure, separate operating means for said movable contacts including manually oparable handles projecting from said enclosure and current responsive elements for automaticaliyreleasing said movable contacts on overload, and a common stationary contact element within said enclosure carring a plurality of contact surfaces in position to be engaged by said movable contacts.

11. In an automatic mu1ti circuit circuit breaker, a base, a stationary contact lament spaced from the main body of the base and carrying a plurality of contact suriaces,'a plurality of movable contact bars having contacts thereon disposed between said contact surfaces and the main body of the base, the ends of the bars remote from said contacts being normally restrained, and individual members about which said bars are adapted to pivot when released, the ends of the bars supporting the contacts movin toward the main body of the base to open the circuit thereth'rough.

12. In an automatic multicircuit circuit breaker, a base, parailel walls on said base, slots in said walls for the reception of movable contact bars, extensions on said walls cooperating with said walls to guide manipuiable members engaging said bars, a stationary contact element carrying a plurality cf contact surfaces supported between a central pair of said walls, and an 1 sulating sheet beneath said contact element having openings receiving the contact tips on said bars, said sheet cooperating with said walls on the base to form an arc chamber.

13. In an automatic 'multi-circuit circuit breaker, a base, a common stationary contact clement carrying a plurality of contact surfaces, a

plurality of movable contacts cooperating there- V respective contacts, and are suppressorsufiaces:

extending on either side of and closely adjacent to the path of movement of said contacts.

14. In an automatic multi-circuit circuit breaker, a base, a common stationary contact element carrylng a plurality cf contact surfaces, a plurality of movable contacts cooperating therewith, individual circuit breaker mechanisms for said movable contacts, said mechanisms being individually manually operable to move their respective contacts and individually automatically operable in response to overload to move their respective contacts, and insulating suppressor plates extending from said stationary contact clement in the direction of movement of said movable contacts, said plates being located on either side of and closely adjacent to their path of movement.

15. In an automatic multi-circuit circuit breaker, a base, a plurality cf circuit breaker mechanisms on said base, a plurality of manually operable handles for said mechanisms, said mechanisms being individually manually operable to separate their contacts and individually automatically operable to separat their contacts in response to an overload and a metallic cover for said circuit breaker having a plurality cf opemngs through which said handles project, said cover being sealably attached to said base and hingedly attached to an enclosing box, said ccver forming part of the cover for said box, and supplemental cover means for closing said box.

16. In an automatic multi-circuit circuit breaker, a base, a plurality of individual circuit breaker mechanisms supported by said base, individual movable contacts actuated by said mechanisms, the cooperating contacts being at least electrically common and supported within the circuit breaker enclosure, the arcs formed between cooperating contacts being interrupted in a common chamber.

17. In an automatic multi-circuit circuit breaker, a base, a plurality of individual circuit breaker mechanisms supported by said base, individual movable contacts actuated by said mechanisms, a common stationary contact plate supporting a plurality et contact surfaces in position to be engaged by said movable contacts, and a common chamber for the interruption of arcs formed by the opening movement of said movable contacts.

18. In a unitary, automatic multi-circuit circuit breaker, a sealable enclosure, a plurality of individual circuit breaker mechanisms within said enclosure, a common terminal for said mechanisms sealable within the enclosure from outside access, and individual opposite terminals for said mechanisms accessibly mounted at the exterior of the enclosure.

19. In an automatic multi-circuit circuit breaker, an enclosure, electrically connected stationary contacts disposed intermediate the nds ci said enclosure, and a plurality of individual.

circuit breaker mechanisms including automatically and manually movable contacts cooperating with said stationary contacts, said mechanisms being disposed between said stationary contacts and the opposite ends of the enclosure.

20. In an automatic multi-circuit' circuit breaker, a sealable enclosure, electrically con nected stationary contacts disposed intermediate -the ends of said enclosure, a plurality cf individual circuit breaker mechanisms including autmatically and manually movable contacts cooperating with said stationary contacts, at least one of said mechanisms being disposed between said stationary contacts and each end of said enclosure.

21. In an automatic multi-circuit circuit breaker, a base, a connected cluster of stationary contacts intermediate the ends of the base, a plurality cf elongated floating members can'inE contact surfaces at one end cooperating with said contacts, the opposite ends of said members extending in opposite directions toward the ends of the base, individual current responsive latching means for said members, andindividual biasing means for moving said members when released by saidlatching means to move their respective contact surfaces to a disengaged position.

22. In an automatic multi-circuit circuit i3reaker, a base, a plurality of electrically connected, closely adjacent stationary contacts disposed intermediate the ends of the'base, a plurality cf movable contact members carrying contact surfaces at one end adapted to ccoperate with said contacts, the opposite ends of said members extending in opposite directions toward the ends of the base, and individual automatic circuit breaker mechanisms for m0ving said members in response to a current overload to cause relative movement betweensaid contact surfaces and contacts.

23. In an automatic multi-circuit circuit breaker, an enclosure, a plurality of at least electrically common stationary contact surfaces within said enclosure, a plurality of elongated, fioating members within said enclosure carrying contact surfaces at one end cooperating With said stationary contact surfaces, individual current responsive latching means for the opposite ends of said members, individual means biasing said members against said contacts and latching at least one elongated, fioating member extending from the cluster toward each end of the enclosure, the ends of said members adjacent said 4 cluster carrying contact surfaces cooperating with said stationary contact surfaces, individual current responsive latching means for the opposite ends of said members, individual means biasing said members against said stationary contact surfaces and latching means, and individual pivotal axes for said members interjacent the biasing means and contact surfaces about which the members rotate when released by said latching means to separate the cooperating contact surfaces.

25-. In an automatic multi-circuit circuit breaker, a pair of electrically connected, closely adjacent stationarycontacts, substantially aligned movable contact members carrying contact surfaces cooperating with said contacts, individual. circuit breaker mechanisms for said members, a magnetic surface extending at one sidqnf the path of movenient of both said contact surfaces, a magnetic surface extending at the other side of the path of movement ofboth said contact surfaces, and a magnetic portion interconnecting said magnetic surfaces.

26. In an automatic multi-circuit circuit breaker, a contact element carrying a plurality of contact surfaces, a plurality of movable contact surfaces, a plurality of movable contacts cooperating with said surfaces, individual circuit breaker mechanisms for said movable contacts, a common magnetic member cooperating with said contacts t assist in quenching an arc drawn therebetween, said member having portions disposed on either sides of the path of the movable contacts and a portion connecting said first mentioned portions.

28. In an automatic multi-eireuit circuit breaker, a pair of electrically connected, closely adjacent, stationary contacts, aligned movable members carrying contact surfaces cooperating with said contacts, individual circuit breaker mechanisms for said members, an

arc suppressor surface extending at one side of the path of movement of both said contact surfaces, and an arc suppressor surface extending at the other side of the path of movement of both said contact surfaces. I

29. In an automatic multi-circuit circuit breaker, a pair of electrically connected, cloeely adjacent stationary contact surfaces, substantially aligned movable members carrying cohtact surfaces cooperating with said stationary contact surfaces, individual circuit breaker mechanisms for said members, surfaces extending on both sides of the path of movement of both said contact surfaces, and liners for said last mentioned surfaces formed of a material to facilitate the arc suppressing function of the surfaces.

30. In an automatic multi-circuit circuit breaker, a base, a plurality of electrically connected, closely adjacent, relatively stationary contacts supported on the base, a plurality of movable contact members carrying contact surfaces co0perating with said contacts, a plurality of individual circuit breaker mechanisms for said members supported on said base, and an arc chamber on said base common to said contacts.

31. In an automatic muIti-circuit circuit breaker, an arc chamber, a plurality of electrical- 137 connected, closely adjacent contacts disposed in said chamber, a plur.lity of movable members carrying contact surfaces within said chamber cooperating with said contacts, and a plurality of individual automatic electric circuit breaker mechanisms for movingsaid members, said chamber facilitating the interruption cf arcs drawn between cooperating contacts and contact surfaces.

32. In an automatic multicircuit circuit breaker, a base, a chamber for arc gases substantially centrally of said base,electrieally connected stationary contacts in said chamber, a plurality of movable members carrying contact surfaces within said chamber cooperating with said contacts, and a plurality of individual automatically and manually actuable circuit breaker mechanisms for moving said members, at least one set of said mmbers and-mechanisms being located between said chamber and each end of the base.

33. In breaker, a base, a cover sealably attachablc to said base to form a unitary enclosure, electrically connected stationary contact surfaces mounted within the enclosure, a plurality of individual substantially an automatic multi-circuit circuit movable contacts cooperating with said contact surfaces, and individual automatically and manually actuable circuit breaker mechanisms Within the enclosure for operating said movable contacts, the manual means for actuating said mechanism projecting through the cover to the exterior of the enclosure.

34. In an automatic multi-circuit circuit breaker, a base, a cover sealably attachable to said base to form a unitary enclosure, 2. stationary contact plate mounted on said base within the enclosure, a plurality of individual movable contacts cooperating with said contact plate, and individual automatically and manually actuable circuit breaker mechanisms within the enclosure for operating said movable contacts, the manual means for actuating said mechanism projecting through the cover to the extericr of the enclosure.

35. In an automatic multi-circuit circuit breaker, a base, a cover sealably attachable to said base to form a unitary enclosure, 3. contact plate mounted on said base intermediate the ends thereof, a plurality of individual movable contacts cooperating with said contact plate, individual automatically and manually actuable circuit breaker mechanisms Within the enclosure for operating said movable contacts, at least one of said mechanisms being located between the contact plate and each end of the enclosure.

36. An ectricircuit breaker assemblage comprisin'g a unitary base having a generaIly centrally disposed dividing wall extending from end to end of the base and dividing it into two sections of opposite polarity, a plurality of stationary contact surfaces disposed intermediate the ends of the base on each side of said dividing wall, the contact surfaces on the same side of the wall being electrically connected and insulated from the contact surfaces at the opposite side of the wall, a plurality cf movable contacts cooperating with said stationary contact surfaces, and individual automatically and manually actuable circuit breaker mechanisms for moving said movable contacts, and cover means sealably attached to said base to enclose said contact surfaces, contacts and mechanisms.

37. An electric circuit breaker assemblage comprising a unitary base having a plurality of deep compartments therein, a generally central dividing wall extending substantiaily from end to end of the base and dividing it into two sections of opposite polarity, a group of electrieally connected stationary contact surfaces disp0sed intermediate the ends of the base on each side of said dividing walls, said groups being of diffrent polarity and electrically insulated from each other, a plurality cf movable members carrying contact surfaces adapted to cooperate with said stationary contact surfaces, and a plurality of individual automatically and manually actuable circuit breaker'mechanisms for moving said members, at least one set of said members and mechanisms, on each side of the dividing wall, being ldcated between the stationary contacts and each end of the base,

38. An electric circuit breaker assemblage comprising a unitary base having a plurality of deep compartmcnts therein, a generally central dividing wall extending substantially from end to end 'Of the base and dividingit into two sections of ity and electricaily insulated from each other. a plurality or movable members carrying contact surfaces adapted to cooperate with said stationary contact surfaces, and a plurality of individual autonmticafly and manually actuable circuit breaker mechanisms for moving said members, at least one set of said members and mechanisms, on each side of the dividing wall, being located between the stationary contacts and each end of the base, and a cover for said base seaiably attachable thereto to prevent unauthorized. access, said mechanisms including manual operating handles projecting through the cover to a readily accessible position.

39. In an automatic multi-circuit circuit breaker, a unitary base having an elongated compartment in substantiai communication :from end to end of the base. eiectrically connected stationary contact surfaces in said compartment and intermediate the ends of the base, said surfaces being adjacent and spaced longitudinafly of the base, substantially aligned movabie members carrying contacts cooperatinz with said stationary contact surfaces, individual automatically and manually actuabie circuit breaker mechanisms for moving said members, said members and mecham8ms beinx disposed between said stationary contact surfaces and the opposite ends of t he base, and cover means sealably enclosing said chamber.

40. In an automatic multi-circuit circuit breaker, a unitary base having an elongated com- -to end of the base,

.for moving said members. said partment in substantial communication from end to end of the base, electricaily connected stationary contact surfaces in said compartment and intermediate the ends of the base, said surfaces being adjacent and spaced longitudinafly of the base, substantialiy alizned movable members carrying contacts cooperating with said stationary contact surfaces. individual automatically and manually actuable circuit breaker for moving said members, said members and mechanisms being disposed between said stationary contact surfaces and the opposite ends cf base, and spaced wails slotted ta prdvide passage for said members and serving'to form an intermediate chamber portion about said contact surfaces and contacts.

41. In an automatic multicfrcuit circuit bxeaker, a unitary basehaving an eionxated compartment in suhstantial communication from end electricafly connected stationary contact surfaces in said compartment and intrmediate t he ends of the base, said surfaces bains adjacent and spaced lonzitudinaily of the base, substantially aligned movable members carrying contacts cooperating with said stationary contact surfaces, individus] automatically and m;inuafly actuable circuit breaker mechanim members and mechanisms being disposed between said stationary contact surfaces and the opposite ends of the base, and insulating formations Serving to substantially isolate the portion of said chamber containing the contact surfaces and contacts from the portions of the chamber containing said mechanisms.

42. In an automatic multi-circuit circuit breaker, a unitary base having an partment in substantial communication frein end to end of the base, electrically connected stationary contact surfaces-in said compartment elongated com- 7 and intermedlate the ends of the base, said surfaces being adjacent and spaced longitudinally of the base, substantially aligned movable members carrying contacts cooperating with said stationary contact surfaces, individual autcmatically and manually actuable circuit breaker mechanisms for moving said members, said members and mechanisms being disposed between said stationary contact surfaces and the opposite ends of the base, insulating formations serving t0 substantially isolate the portion of said chamber containing the contact surfaces and contacts from the portions of the chamber containing said mechanisms, and at least partial barrier means in said intermediate chamber portion between the cooperating pairs of stationary contact surfaces and movable contacts.

43. In an automatic electric circuit breaker a base having at least one cup-shaped compartment therein an end wall of said compartment being shorter than the side walls thereof and having a substantial thickness to form an exterior ledge a connector mounted on said ledge to form a terminal for the circuit breaker and leading into the interior of the compartment. electric circuit breaker mechanism within said compartment and includin separable contacts and automatic and manual means for separating said contacts, and an insulating barrier sheet spanning said side walls adjacent to said end wall and directed toward said connector to close the end opening into said compartment in front of the ledge.

44. In an automatic electric circuit breaker, a base having at least one cup-shaped compartment therein, an end wall of said compartment being shorter than the side Walls thereof and having a substantial thickness to form an exterior ledge, a connector mounted on said ledge to form a terminal for the circuit breaker and leading into the lnterior of the compartment, breaker mechanism within said compartment and including separable contacts and automatic and manual means for separating said contacts, and an insulating barrier sheet spanning said side walls adjacent to said end wall and directed toward said connector to close the end opening into said compartment in front of the ledge. said barrier sheet being interlocked with the side walls of the compartment so that movement thereof is prevented except forwardly of the base.

45. In an automatic electric circuit breaker, a base having at least one cup-shaped compartment therein, an end wail of said compartment being shorter than the side wails thereof and having a substantial thickness to form an exterior ledge, a connector mounted on said ledge to form a terminal for the circuit breaker and leading into the interior of the compartment, electric circuit breaker mechanism within said compartment and including separable contacts and automatic and manual means for separating said contacts. au insulating barrier sheet spanning said side walls adjacent to said end wall and directed toward said connector to close the end opening into said compartment in front of the ledge, said barrier sheet being interlocked with the side walls of the compartment so that movement thereof is prevented except forwardly of the base, and a cover sealably attached to the front of said base and preventing removal of said barrier sheet.

JOHN G. JACKSON.

electric circuit 

